Question

我有一个代表树的类：

public class Tree
{
    public String id { get; set; }
    public String text { get; set; }
    public List<Tree> item { get; set; }
    public string im0 { get; set; }
    public string im1 { get; set; }
    public string im2 { get; set; }
    public String parentId { get; set; }

    public Tree()
    {
        id = "0";
        text = "";
        item = new List<Tree>();
    }
}

树看起来像这样：

tree    {Tree}  Tree
  id    "0" string
  im0   null    string
  im1   null    string
  im2   null    string
  item  Count = 1   System.Collections.Generic.List<Tree>
    [0] {Tree}  Tree
            id  "F_1"   string
            im0 "fC.gif"    string
            im1 "fO.gif"    string
            im2 "fC.gif"    string
            item    Count = 12  System.Collections.Generic.List<Tree>
            parentId    "0" string
            text    "ok"    string
    parentId    null    string
    text    ""  string

如何删除id = someId？

的节点

例如，如何删除id =“F_123”的节点？它的所有孩子也应该被删除。

我有一个方法可以在树中搜索给定的id。我尝试使用该方法，然后将节点设置为null，但它不起作用。

这是我到现在所得到的：

//This is the whole tree:
Tree tree = serializer.Deserialize<Tree>(someString);

//this is the tree whose root is the parent of the node I want to delete:
List<Tree> parentTree = Tree.Search("F_123", tree).First().item;

//This is the node I want to delete:
var child = parentTree.First(p => p.id == id);

如何从树中删除孩子？

Answer 1

所以这是一个公平直接的遍历算法，可以获得给定节点的父节点;它使用显式堆栈而不是使用递归来实现。

public static Tree GetParent(Tree root, string nodeId)
{
    var stack = new Stack<Tree>();
    stack.Push(root);

    while (stack.Any())
    {
        var parent = stack.Pop();

        foreach (var child in parent.item)
        {
            if (child.id == nodeId)
                return parent;

            stack.Push(child);
        }
    }

    return null;//not found
}

使用它很简单，通过找到它的父节点然后从直接后代中删除它来删除节点：

public static void RemoveNode(Tree root, string nodeId)
{
    var parent = GetParent(root, nodeId).item
        .RemoveAll(child => child.id == nodeId);
}

Answer 2

找到要删除的节点的父节点（id = F_1）。递归地从树中删除它

// something like
Tree parent = FindParentNodeOf("F_1");
var child = parent.Items.First(p=> p.id="F_1");
RecurseDelete(parent, child);

private void RecurseDelete(Tree theTree, Tree toDelete)
{
    foreach(var child in toDelete.item)
       RecurseDelete(toDelete, child);

    theTree.item.Remove(toDelete);
}

从树状结构中删除节点

2 个答案: